<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>判断当前季节</title>
</head>
<body>
    <script>
        var a=11;
        var b ="";
        switch(a){
            case 3:
            case 4:
            case 5:
            b="春天"
            break;
            case 6:
            case 7:
            case 8:
            b="夏天"
            break
            case 9:
            case 10:
            case 11:
            b="秋天"
            break
            case 12:
            case 1:
            case 2:
            b="冬天"
            break
        }
        document.write("当前季节为："+b)
    </script>
</body>
</html>